"My job is much more difficult." I don't think anyone realizes how hard someone else's job is until they try it. Whether or not someone job is easier than yours, is a wild thing to assume.

If his job earns more money, it's more likely his job is complicated. Complicated job requires a lot more thought and effort

So he's fine with you taking time off work to study and pay the difference. But you're angry when he took time off to both spend with you and STUDY that he didn't do enough? You're gonna end up doing more if one of you is trying to study, surely you understand that

Did you and your husband work the same amount at this time?